The truck driver proceeds forward, but instead of merging to the left onto northbound Enrico Fermi Drive as all of the trucks have been doing, he makes a broad turn to the right and follows cones around the east side of the building and finally into the inspection garage from the south. Vail leads me through the office -- on the way pointing out a South Bay municipal court desk where drivers can pay court fines and a DMV desk where they can pay registration dues -- to the inspection area where the blue truck is being guided into bay number two by one of the inspectors. "There's the guy we were looking at coming in for his inspection. First, the inspector will check the driver, then he'll start the inspection. He'll go over the rig checking critical items: steering, suspension, tires, brakes, the major items that can cause an accident. He puts the information in the computer. From start to finish, it's usually about a half an hour."

If the truck being inspected has no violations, it will receive a new sticker, and unless an officer spots a violation the next time it goes through the scale, it won't be inspected until next quarter. If the inspector finds a minor violation, the driver will be given a warning ticket and sent on his way. If the violation is serious enough, a ticket bearing a $10 fine will be given and, after he pays the fine, the driver will be sent through. The next time either of these first two drivers comes in for his routine quarterly inspection, special attention will be paid to the items he was ordered to fix. If he still hasn't fixed them, he will be given a fine-carrying ticket for disobeying an officer's order.

If an inspector decides a violation meets the out-of-service criteria set by the Commercial Vehicle Safety Alliance (made up of all 50 states, some provinces in Canada, some states in Mexico), "We park them," Vail explains, "and they have to fix it before they go or they've got to get their own big-rig tow, and they can tow it back to Mexico or someplace for repairs. Otherwise, they have to fix it here. If they have their own mechanics, they can come in and fix it. We give them about 48 hours. We figure that's enough time. If they're not trying to effect repairs during that time, we'll tow it out of here. If they come to us and say they've got a part coming, we'll let it sit there. But if two or three days go by and nothing appears to be done, we impound it."

Vail adds, "Our focus is mechanical safety. It used to be mechanical violations caused many accidents, but now the vast majority are caused by driver violations. I think it's because the CHP in California have really invested time, money, and training into making these trucks safe. We hit a lot of trucks not only here at the border but at all the other scale facilities plus our mobile road-enforcement guys. I think that's why the crashes due to mechanical malfunction is low, 3 to 5 percent. The other 95 percent is driver error, because you can't control that."